Abstract: This paper investigated the effects of the most two commonly used microcapsule drying technology,spray drying and vacuum freeze drying,on the quality of peony seed oil microcapsules. The embedding rates of peony seed oil microcapsules prepared by spray drying and freeze drying methods were 88.12% and 76.55%,respectively. The moisture content,solubility and color were significantly different(P<0.05). Spray-dried microcapsules were spherical,smooth without wrinkles. And the particle size distributions followed a normal distribution and the average particle size was 2 563 nm. While,cold-dried microcapsules were irregular flakes with depressions and holes on the surface,and the particle size distribution didn't follow a normal distribution and the average particle size was 765.5 nm. From the FTIR curve,in the microcapsule products prepared by the two drying methods,the core material was covered by the wall material. Moreover,no significant difference in fatty acid composition of peony seed oil microcapsules prepared by two drying methods(P<0.05). The microencapsulation of peony seed oil was beneficial to maintain the thermal stability and oxidation stability of peony seeds oil,and high temperature above 200 ℃ could decompose the wall material. Furthermore,the oxidation stability of microcapsules prepared by spray drying method was better than that of cold drying method. In summary,spray drying is a better process condition for preparing peony seed oil microcapsules than freeze drying.
TONON R V,GROSSO C R F,HUBINGER M D. Influence of emulsion composition and inlet air temperature on the microencapsulation of flaxseed oil by spray drying[J]. Food Research International,2011,44(1):282-289.
TATAR F,TUNÇ M T,DERVISOGLU M,et al.Evaluation of hemicellulose as a coating material with gum arabic for food microencapsulation[J]. Food Research International,2014,57:168-175.
JAYASUNDERA M,ADHIKARI B,HOWES T,et al.Surface protein coverage and its implications on spray-drying of model sugar-rich foods: Solubility,powder production and characterisation[J]. Food Chemistry,2011,128(4):1 003-1 016.